Container closure



16, 1967 H. OSTWAL-D CONTAINER CLOSURE Filed Dec. 4, 1964 2 Sheets-Sheet 1 INVENTOR Henry OSTWALD AGENT y 1967 H. OSTWALD 3,319,869

CONTAINER CLOSURE Filed Dec. 4. 1964 2 Sheets-Sheet 2 INVENTOR Henry USTWALD AGEN:

United States Patent Ofiice 3,319,869 CONTAINER (ILUSURE Henry Ostwald, Winnipeg, Manitoba, Canada, assignor to Dominion Tar & (Ihernical Company, Limited, Montreal, Quebec, Canada Fiied Dec. 4, 1964, Ser. No. 416,055 tjlaims. (Cl. 229-39) The present invention relates to a container closure, more particularly to a releasable type closure means for paperboard boxes.

The present closure is of particular value in the packaging industry, especially for the packaging of bottles or the like, wherein the carton is carried along on a conveyor to and from the filling station and where the bottom closure is finally secured after the filling station. If the bottom flaps of the carton to be filled are not temporarily held when it is being fed along the conveyor, the cartons do not ride evenly on the conveyor. Furthermore, difficulty is encountered in maintaining the cartons square as they pass through the fillin station. The present invention provides a simple but effective method of overcoming these difiiculties.

Thus, it is an object of this invention to provide a simple but effective releasable closure means for cartons.

The closure mechanism of the present invention has a dual function in that it not only holds the closure flaps in closed elevated position, but also tends to prevent the box itself from being deflected from a squared position.

Broadly, applicant provides a system whereby the locking of the closure is accomplished simply by pressure on one flap of a pair of opposite flaps and release of the flaps is obtained similarly by pressure on the surface of the other of said .pair of fiaps. In locked position the bottom flaps are held out of the way so that an empty carton may travel freely along the conveyor.

Further features, objects and advantages will be evident from the following detailed description taken in conjunction with the accompanying drawings in which FIG. 1 is a prospective view of a carton equipped with the present invention.

FIG. 2 is a plan View showing the side flaps in position to be folded down.

FIG. 3 is a plan view showing the closure flaps folded down in overlapping relationship and FIG. 4 shows the closure in locked position.

Referring to FIG. 1, the box 18 is provided with two pairs of oppositely directed end closures, flaps 12 and 14, and 16 and 18 respectively. The present invention has been applied to the pair of flaps 16 and 18.

As shown, the flap 16 has an M shaped notch 22 cut at the centre of its free edge 24 while the flap 18 is merely straight edged. The bottom of the notch 22 has, in this embodiment, a V shaped projection 26 which serves as a locking tab to hold the flaps 16 and 18 and thus flaps 12 and 14 in closed relationship. A pair of score lines 28 and 30 extend across the flap 16 from adjacent the month of notch 22 at the free edge 24 to the adjacent attached corners of said flap. A similar pair of score lines 32 and 24 extend from near the centre of the free edge 36 to the attached corners of the flap 18. These score lines 28, 3d, 32 and 34 allow the flaps 16 and 18 to be easily deflected when placing said flaps into locking position as will be more particularly pointed out hereinafter.

The combined lengths of flaps 16 and 18 minus the depth of notch 22 should be at least equal to the length of side wall 20 of the box and is preferably slightly longer than the length of said wall. If any locking at all is to be obtained, the combined length must be such that when the flaps are in closed position, the tab 26 overlies the free end of the flap 18.

3,319,889 Patented May 16, 1967 In the preferred embodiment, the combined length of flaps 16 and 18 less the depth of notch 22 is longer than the length of wall 20 as above indicated. Thus, in order to close and lock the end of the carton, the flaps 16 and 18 must be deflected toward the interior of the box to push the edge 36 of flap 18 past the end of projection 26. Also, when the flap 18 is locked in position within the notch 22, flaps 16 and 18 will remain deflected toward the interior of the box with the edge 36 pushed against the bottom of the notch 22 due to the tendency of the flaps 16 and 18 to return to their normal positions. This pressure serves to hold the flaps 16 and 18 and thus the box closure in closed relationship. The centre portion of these flaps 16 and 18, when in closed position, extend inwardly toward the centre of the carton to allow the cartons to move freely along a conveyor since the flaps are held up out of the way. Furthermore, pressure simultaneously applied to the flaps 16 and 18 from the interior of the carton must first increase the force of edge 36 against the notch 22 before the closure may be opened by internal pressure.

As above described, the centre of the flaps 16 and 18 are deflected in towards the centre of the interior of the box 1'8. The lateral free edges 38 and 40 of flap 16, and 42 and 44 of flap 18 (see FIG. 1) cannot move in toward the interior of the box due to contact with the corners of flaps 12 and 14. and thus the score lines 28, 30, 32 and 34- are provided to permit deflection of flaps l6 and 18. These score lines allow the central portion adjacent the free edges 24 and 36 of flaps 16 and 18 to be easily pushed in towards the centre of the box 10.

The ends of score lines 32 and 34 should be spaced at the edge 36 a distance less than the opening or width or gap 22 and should be such that any portion of flap 18 that overlaps the flap 16 when in locked position is free to flex outwardly. In other words, the score lines 32 and 34, when the box is in locked position, would extend from the outside attached corners to the edge 36 of flap 18, said lines being spaced less than the opening at the mouth of notch 22 at a distance in from the edge 36 equal to the depth of notch 22. Preferably, this spacing will be equal or slightly less than the opening at the mouth of notch 22. Attention is directed to FIG. 4- which illustrates the position of the various score lines 32 and 34 in relation to the mouth of notch 22 of the opposite flap.

Score lines 28 and 30 are conveniently located to extend from adjacent the mouth of notch 22 to the attached corners of the flap 16. These score lines 28 and 38 serve a similar purpose to lines 32 and 34 and allow the centre of flap 16 to be more easily displaced in toward the center of the box 18.

Operation of the closure will now be described with reference to FIGS. 2, 3 and 4. FIG. 2 shows the flaps 12 and 14 folded inwardly and the flaps 16 and 18 being manipulated. These flaps 16 and 18 are folded so that the flap 18 or the flap provided with a straight edge overlaps the flap 16 or notched flap as shown in FIG. 3. Pressure is then applied to the exposed flap 18 at a point adjacent the centre of the edge 36 between score lines 32 and 34 to force the edge 36 past the projection 26 and into the notch 22. This pressure is then released and the flaps 16 and 18 are held together by the projections 26 overlapping the flap 18 and by the tendency of the flaps 16 and 18 to resume their original positions which forces the edge 36 against the bottom of the notch 22 (see FIG. 4).

Release of the closure from the locked or closed position is readily accomplished by simply applying pressure to move the flap 16 or the underlying flap so that the projection 26 moves along the surface of flap 18 until the edge 36 escapes from under said projection 26. When 3 the edge 36 escapes the flap 13 will spring away from the flap 16 and by releasing the flap 16, it will also spring away from the centre to leave the closure flaps 16 and 18 in open position as illustrated in FIG. 2.

When utilizing the present closure mechanism as a bottom temporary closure during packaging, it is simply necessary to fold in the flaps 12, 14, 16 and 18 so that flap 18 is exposed as above described, to square the box 10 and then to apply pressure to flap 18 and force the edge 36 into the notch 22 below the projection 26. The pressure of the edge 36 against the bottom of notch 22 tends to prevent the carton from leaving the squared position and the closed bottom stabilizes the container for riding on a conveyor. Furthermore, since the flaps 16 and 18, when locked, extend upward into the interior of the carton, only the edges of the empty carton contact the conveyor. This has the advantage of reducing the tendency for any of the bottom flaps to be caught on the conveyor since these flaps are held up in the interior of the carton.

In the preferred carton the flaps 16 and 18 are designed to yield and be deflected from the interior of the carton by the weight of the material filling the carton. In other words, the weight of the material filling the carton should force flaps 16 and 18 down against a supporting conveyor. With the flaps so deflected, usual opening procedures utilizing plows or the like are applied to open said flaps while preventing the material filling the carton from fall ing through the bottom. After the flaps 16 and 18 have been opened, glue is applied to same and these fiaps are then re-folded to permanently close the bottom of the carton. When the flaps 16 and 18 are glued together, the locking means including notch 22 serves no locking function.

A specific example of a box made in accordance with the present invention has a length of about 12 /2 inches and a Width of about 8 /2 inches. The flaps 16 and 18 are each approximately inches long and thus their combined length is inches. The depth of notch 22 is about /1 inch and the projection 26 extends from the bottom of the notch about inch. Therefore, when the flaps are in closed position with flap 18 in the notch 22, the combined length of flaps 16 and 18 minus the depth of notch 22 is about 9% inches or 4 inch longer than the 8 /2 inch width they span. The mouth of the notch is a little wider than 2' inches and the spacing of the score lines 32 and 34 at the edge 36 is about /2 inch.

Thus, applicant has disclosed a simple but effective device releasably holding container flaps closed. While this application has dealt with utilization of the instant invention in only one environment, further uses will be apparent to anyone skilled in the art.

I claim:

1. A carton having at least one pair of opposed closure flaps, locking means for holding said pairof flaps in closed position, said locking means including a notch adjacent the centre of the free edge of one flap of the pair of flaps, a tab projecting outward from the bottom of said notch, the other flap of said pair of fiaps co-operating with said notch and tab to 'releasably lock said carton closed, the combined lengths of said pair of flaps minus the depth of said notch being longer than the distance to be spanned by said pair of flaps so that at least the central portions adjacent the free edges of said pair of flaps extend into said carton when said one flap and said other flap are in locked position.

2. A carton as defined in claim 1 wherein said one flap of said pair of flaps has crease lines extending from each side of the mouth of said notch to the adjacent attached corner of said one flap.

3. A carton as defined in claim 1 wherein crease lines extend from adjacent the centre of the free edge of said other of said pair of flaps to the adjacent attached corners of said other flaps.

4. A carton as defined in claim 1 wherein said one flap of said pair of flaps has a pair of crease lines extending from each side of the mouth of said notch to the adjacent attached corner of said one flap, and wherein a further pair of crease lines extending across the other flap of said pair of flaps from adjacent the centre of the free edge of said other flap to the adjacent attached corners of said other flap.

5. A carton closure comprising; a pair of opposed closure flaps, each of said closure flaps being hingedly attached along one edge to a wall of said carton and having a free edge opposite said one edge, a second edge centrally located relative to the free edge on one of said pair of flaps, said second edge defining the periphery of a locking tab, the opposite ends of said second edge being substantially equally spaced from said free edge of said one flap by a first distance, a section of said second edge between said ends being spaced from said free edge of said one flap by a second distance, said second distance being shorter than said first distance, said second edge engaging said free edge of the other flap of said pair of flaps and said other flap underlying said locking tab when said flaps are in locked position, the combined length of said pair of flaps minus said first distance being Wider than the carton width to be spanned by said flaps, whereby a middle portion of said flaps adjacent said free edges extends into said carton when said flaps are in locked position.

References Cited by the Examiner UNITED STATES PATENTS 2,091,291 8/1937 Ringler 22941 2,811,817 11/1957 Mojonnier 5337 3,107,840 10/ 1963 Vesak 22939 JOSEPH R. LECLAIR, Primary Examiner.

GEORGE O. RALSTON, Examiner.

R. PESHOCK, Assistant Examiner. 

1. A CARTON HAVING AT LEAST ONE PAIR OF OPPOSED CLOSURE FLAPS, LOCKING MEANS FOR HOLDING SAID PAIR OF FLAPS IN CLOSED POSITION, SAID LOCKING MEANS INCLUDING A NOTCH ADJACENT THE CENTRE OF THE FREE EDGE OF ONE FLAP OF THE PAIR OF FLAPS, A TAB PROJECTING OUTWARD FROM THE BOTTOM OF SAID NOTCH, THE OTHER FLAP OF SAID PAIR OF FLAPS CO-OPERATING WITH SAID NOTCH AND TAB TO RELEASABLY LOCK SAID CARTON CLOSED, THE COMBINED LENGTHS OF SAID PAIR OF FLAPS MINUS THE DEPTH OF SAID NOTCH BEING LONGER THAN THE DISTANCE TO BE SPANNED BY SAID PAIR OF FLAPS SO THAT AT LEAST THE CENTRAL PORTIONS ADJACENT THE FREE EDGES OF SAID PAIR OF FLAPS EXTEND INTO SAID CARTON WHEN SAID ONE FLAP AND SAID OTHER FLAP ARE IN LOCKED POSITION. 